1. Visiting Scientist from Istituto di Anestesiologia e Rianimazione, Universitã degli Studi di Padova, 35100 Padova, Italy.
2. Predoctoral Student, University of Maryland, School of Pharmacy, Department of Pharmacology and Toxicology, Baltimore, Maryland.
3. Chief, Neuropharmacology Laboratory, NIDA Addiction Research Center.